Inherent qualities of colours

Cool colours: purple, blue, green. They seem to recede into the distance and offer stability. This implies their effective use as background colours.
Warm colours: red, yellow, orange. They appear to advance toward the viewer, implying foreground use.
Brilliance levels send messages as well. A reduction in brilliance adds warmth (such as oink istead of red). Lighter colours seem to have less weight than dark colours. Colours exhibit less brilliance in the distance than in the foreground.
If you intend to create visuals that convey realism, analyzing the world around you is a great place to start.

Concordance, Conflict, and Contrast

Remember these three principles from textual design. They can be used just as effetively when applying colour. Keep in mind the adage "Don't be a wimp". If you are looking for a certain exaggerated effect, don't go just halfway.